+1. I have a great ceramic coating guy local (thanks motor city) that does work for my business and will certainly be doing mine once the porting is complete.

 

Hi,Thanks....I might,I will let you know

 

I ported and ceramic coated only the outside. I was concered the coating would come off on the inside and get stuck in the turbine wheels.......lets face it they can't get the inside perfectly prepped for perfect adhesion...... anyone ever done the inside or even the turbine wheels coated?......results?

 

I went to my Porshe dealer to look at another set of used manifolds they had laying around in the shop because they were cracked.Wow...They had lots of weld in them compared to the ones I just bought......Its so hard to believe that a small collector diameter like that can flow enough to make the power these modified cars do.....

 

This is what a set of equal length vs OEM TT headers looks like, both available cheaply from me as previously noted

 

Hey Guys,,I finally took off my original factory exhaust headers to put on a freshly ported set and also to change my cats out...Guess what,,,my 2004 manifolds looked real good,not as bad as the ones you showed in these pictures...Hardly any weld sticking out into the merge collector and the ports only had very few spotted areas in the way.......All in all,I was hoping for them to be bad to justify this swap but I do not know if it was worth it???...I did talk to a couple of coaters,Swain and Calico...they kinda told me that since are headers have short tubes,stainless and being double walled,that there really was no need to coat them for a performance stand point only because the gases are so hot and moving at a very fast rate that they would not cool down enough to hurt regardless..I agree with them...Hope this helps......

 

I personally would not do this unless you are running turbos larger than k24s. Exhaust gas velocity is important on turbo manifolds. You can open the manifolds up more to increase flow, but the velocity of the exhaust gases will be reduced. This can effect turbo spool and response. I can't see the flow of the manifolds being a limiting factor until you get above K24 turbos in size.

As for the heat coatings, they definately have their place in the turbo world. When I had the B5 S4 I knew of several people that drastically reduced the under hood temps of the engine bay using these coatings. The high temps would bake the sensors and cause early failure especially when running high boost. The 996TT has been engineered very well in terms of air flow. The engine bay of the 996TT gets much more cooling air than the B5 S4. The air flow around the manifolds is soo much that I would bet that the swain tech coatings would yield minimal actual results. I wouldn't do the coatings unless I saw an actual issue caused by the exhaust heat.

 

I agree.......But usually when you take weld flashing and glumps of weld out of certain areas besides increasing flow,you also increase velocity....Many flow benches have proven this..I do have K24/18gs which are bigger then K24's,as it says in my signature.Still the stock ported headers are a better choice then after market ones.I have seen this personally on a dyno comparision....I also agree with coatings do help in other areas and other cars that suffer from under the hood heat issues,cheap single wall material and very long tube headers,,But we do not have these problem....Unless we want to work under our cars right after we shut it off...lol.....Havea great day.......

 

I agree that cleaning up the inside of the pipes would be a good improvement regardless of turbo size. The one issue that arises with some turbo setups when you change the manifold diameter is the gas flow. You will increase HP in many scenarios by porting the manifold, but is often times at the cost of increased turbo lag. The decrease in gas velocity slows turbo spool time. That is why I believe careful consideration must be taken when deciding whether or not to port headers.